FAQs
Find the answer to your question here, or contact us at sales@norwegian-subsea.no.
Find the answer to your question here, or contact us at sales@norwegian-subsea.no.
The MRU Compact uses a standard RJ45 ethernet cable where power is supplied through Passive PoE (Power over Ethernet). In most cases you cannot connect the MRU directly to a an ethernet switch with PoE, since most of these are Active PoE.
We normally supply your first MRU Compact with a start kit containing a POE RJ45 spliter socket. You will only need standard RJ45 cat5 ethernet cables to connect the MRU to the spliter socket and the spliter socket to your PC or ethernet switch.
The MRU dimensions depend on the selected casing.
The MRU Compact is also available with a RJ50 connector instead of the standard RJ45 Ethernet connector.
The RJ50 connector (also called 10P10C connector) is identical in shape to the RJ45 connector but has 10 wires. The outside 2 pins on a RJ45 connector are blind but these are in use for the RJ50 connector.
Choosing the right motion sensor ensures optimal performance and reliability for your specific needs. At Norwegian Subsea, we offer a range of high-performance Motion Reference Units (MRUs) designed for diverse marine, subsea, and offshore applications. The selection process primarily depends on the operational environment, required accuracy, connectivity needs, and specific functionality.
First, consider the installation environment. Our MRU Compact (IP65) is ideal for indoor or control box mounting, featuring easy plug-and-play installation with passive Power over Ethernet (PoE) via an RJ45 connector. For on-deck or shallow subsea applications (up to 50m), the MRU Marine (IP68) provides robust performance with versatile connectivity options including Ethernet, RS-232/485, and PPS. For deep-water applications up to 6000m, the MRU Subsea offers a compact, high-pressure titanium housing with Subconn connectors. If operating in hazardous areas, the MRU Ex provides a certified stainless steel solution (II 2 G Ex d IIC Gb).
Motion Reference Unit (MRU)
Definition: A motion Reference Unit (MRU) is a specialized device and self-contained sensor that measures motion in all six degrees of freedom (DoF): Roll, Pitch, Yaw, Surge, Sway and Heave. The six DoF positions, velocities and accelerations are measured by the MRU using high-end gyroscopes and accelerometers (and sometimes magnetometers) together with advanced fusion algorithms. An MRU has high accuracy Roll and Pitch measurements, and measures oscillatory Heave, Surge and Sway motions for wave periods at sea. Linear motions with very long periods, or steps, cannot be measured by an MRU as it assumes a 0 mean heave position.